You are so cute. I love how you support morality. Unfortunately, the courts don't see things this way.
Sadly, I think the LBS only has so much control. More money and a better lawyer helps. But exposure to OP is inevitable. It's going to happen sooner or later. And trying to control this often makes the spouse angrier and the whole D get's uglier.
On the other hand, trying to manipulate the situation to get more custody may be helpful. For example, explaining to the WAS that you want to help them focus on their relationship with the OP, make sure they get plenty of romantic alone time, etc.... (gag me!!! presenting it like you are doing them a huge favor by taking over most of the custody). You can even present it as temporary... like once they get settled or remarried you can change custody arrangements (Don't put this in writing anywhere... just an offhanded VERBAL suggestion, a maybe.... you have to appear generous!). Of course, once a good custody settlement is approved by the court you stick with it. They come back a year later wanting to change things... well, too bad bud!!!
There is no arriving, ever. It is all a continual becoming.